20 Days of 2D AutoCAD exercises #18

Welcome to Day #18.

Today's AutoCAD exercise consists of the following. We have this simple figure to replicate given all dimensions.


Complementary information


Today's exercise have been conceived with the aim to have you use  all what you have learned so far. But we will have to draw our first polygon today.

The 6 point start in the design is easily replicated using a polygon with 6 sides. You might want to check how to draw a 5 point start in AutoCAD to apprehend how you can go about this.

The POLYGON command


Notice that the star is Circumscribed about the circle of R12.7 in our exercise.

There is actually two ways to draw a polygon in AutoCAD: Inscribed in circle/Circumscribed about circle. And the information you need to provide will be, the center and the radius of the circumscribed circle or inscribed circle. Play around with both possibilities and notice the difference.

You are free to use whatever technique you master best to have this exercise done, but I will suggest you explore and trying different things for experiment sake.

Feel free to drop a comment if you don't understand something in today's exercise. Like this if it helped you, and see you on the next 2D AutoCAD exercise.



The whole series
AutoCAD Exercises #1Drawing your first piece of 2D using AutoCAD. Using LINE command and fixing your settings for a better user experience. Learning how to use coordinates and Using exclusively the command window to draw.
AutoCAD Exercises #2Learning how to draw straight lines with definite dimensions. Basic concept for daily use while working with AutoCAD
AutoCAD Exercises #3Learning the use of OSNAP and using skills you gained to design a more complex 2D.
AutoCAD Exercises #4Using some math and drawing lines with specific angles and dimensions. Learning the basic concept of angles in AutoCAD, and actually using the trick main while.
AutoCAD Exercises #5FILLET command and the use of OSNAP. Learning how to place object. Learning how to use center points.
AutoCAD Exercises #6CHAMFER command. Using the CHAMFER command and leaning more about the command window.
AutoCAD Exercises #7how to use HATCH in AutoCAD. You will need skills from Day #4 to have the exercise done, and you will learn how to actually use the HATCH command.
AutoCAD Exercises #8Playing with the TANGENT feature of the OSNAP. You will have a complex figure to replicate, and you will have to learn how the TANGENT feature of the OSNAP works. You will also have to learn a new trick on how to draw a circle using this very technique.
AutoCAD Exercises #9Clear description on how the ARC command works and a complex exercise to try the technique out. All instructions are given for you to easily assimilate the tutorial.
AutoCAD Exercises #10Tricky exercise. You will have to use all technique you have learned in previous exercises to accomplish this one. Hints are given. And an opportunity to ask questions is as well given
AutoCAD Exercises #11Concrete exercise where you will have to see advantages of learning the ARRAY command. A Polar Array is designed and some old techniques you must have learned from the beginning will be helpful.
AutoCAD Exercises #12We have more than an exercise, The aim is to force you to use the ARRAY command. A rectangular Array is to be created.
AutoCAD Exercises #13MIRROR command. The mirror command has not been used since the beginning. This exercise makes it impossible for you if you don't use the MIRROR command. Learning the concept of symmetry in AutoCAD
AutoCAD Exercises #14Create a layers and changing line type. Using the ROTATE command and the OFFSET command. Learning how to combine a set of techniques toward something definite.
AutoCAD Exercises #15Using the combination of all techniques learned so far to come to achieve a complex 2D AutoCAD exercise. Previous learned techniques will be needed in this session and a little bit of math too.
AutoCAD Exercises #16This is a nice AutoCAD exercise that will make you test what you have learned so far. It is testing you ability to combine all you know to get a quite tough exercise done. Of course, hints have been provided to help you get it done.
AutoCAD Exercises #17Revision exercise. Be ready to use your calculator. You will need a bit more of precision in this session. An emphasis has been made on the ROTATE command, OFFSET command and FILLET command in this exercise.
AutoCAD Exercises #18Learning how to draw a polygon in AutoCAD. Here is shown how you can easily construct perfect star in AutoCAD, you may want to convert it into a block for future use. A complex figure is provided as well to help you practice.
AutoCAD Exercises #19Learning how to construct a complex drawing using technique provided to you in previous sessions. This serves as a test, to see how far you have gone since the beginning of this series of exercises.
AutoCAD Exercises #20Exam Day. Grab your Exam eBook for free and come back to me with questions and suggestions on how to make this course easier to understand if possible.
cad exercises
  • caine

    I think you have a measurement wrong.
    The horizontal lines are spaced 2.5 and 4.5.
    All of those added together equal 34 or 17×2.
    The 2 radius’s, 9 and 7 equal 16.
    I think that 9 radius should be 10.
    Is that correct or am i missing something?

    • Antone

      You surely are making a mistake. The horizontal lines are spaced by 4.5 for the ones at the sides (up and down), and 2.5 for ones in between

  • Rashid

    I think theres something wrong here but finally I figured it out with my own.

    • Antone


  • RashidBalza


  • Bob

    How do you know the lengths and starting positions of all the 5 shapes between the star and the circle at he other side of the drawing. I can’t get my head round it!!

  • Tuna Ficilar

    Is there something what I´m too blind to see? I can´t draw it, it seems like there is one measurment missing. It´s not the start what I have problems with but the right side of this drawing. Where are the centers for the circles that I have to draw?

  • Tuna Ficilar

    Can somebody please be so kind to explain this drawing to me?

    • Mira

      I am not sure if I did this correctly but here is what I did.

      First, the polygon is inscribed, not circumscribed.

      For the circle with radius 35.83, I knew the center would be on the axis of symmetry. We know the distance is 80 between the two circles on the ends. So I did 80 – 9.5 – 2(25.14) – 2.5 + 35.83 to find the x-coordinate of its center, 53.55 The circle with R15 I centered at the origin, so this circle has a center of (53.55 , 0).

      For the straight lines, I used the Quadrant on the R9 circles on the right, and extended the line from there until it intersected the R25 circle on the left.

      For the right side of the horizontal bars though, I think I am absolutely wrong. I used an offset of 5 on the R9 circles, however they look off to me based on the original. I assumed the centers of the circles on the right are vertically aligned, but I think I was wrong to make that assumption.

      Any insight is welcome 🙂

      • Tuna Ficilar

        Hi Mira, I think we can give up on this drawing because there is some essential data missing so I strongly assume that the author forgot to provide us with some measures. The results of the data above will never get you to the same picture so don´t waste your time with this drawing cause it will be negative training.

        • Mira

          Hello. I actually figured it out. My assumption about the centers being vertically aligned was correct. The top and bottom straight lines are 1 unit displaced from the R9 circle’s center, however. That could be inferred from the original measurements Antone gave because the total distance between the horizontal lines can be calculated to be 34 = 2(4.5) + 8(2.5). I originally assumed the top and bottom lines were horizontally aligned with the R9 circles’ centers, but that gives a total distance of 32.

      • Andrew

        Where do you get the numbers to get the origin of the radius 35.83 circle?

  • Bibs

    I think I nailed this drawing, even though I feel like some measure there might be missing, I was able to assume where to place the R35,83 circle. Thing is, I started by making the R9 Circles that are vertically alligned with the R5 and R7 circles, all you have to do is make a line that measures 9 and starts vertically alligned with the R7 circle center from the border outwards. repeat or mirror for the other circle; Then I made a line from the borders of the R7 to R15 Circles. That line should measure 60. Then, just make a line from the center of the previous line to the left that measures the 25,14. You can delete the 60 line. Create the R2,5 circle at the edge of the 25,14 line and then you can create a circle with R35,83, It doesn’t matter where ’cause then you just have to use Move, and relocate it so that it’s tangent to the R2,5 circle, whereas the center must be horizontally alligned with the R25, R15, R7, R5 and R2,5 circles. then you just have to repeat the 25,14 line to the right and make the other R2,5 circle. I think you can figure out out to make the other lines. I hope I was helpfull, sorry if I am confusing, english isn’t my mother language but I am happy to provide with help and prt scs if need be ^^

  • Pedro Nuno

    Do you use the metric system on the tutorials or inches?.
    I can’t find any reference to what system you use and I would like to use the same as you.